Control of droplet impact through magnetic actuation of surface microstructures

Jezeršek, Matija (author), Kriegl, Raphael (author), Kravanja, Gaia (author), Hribar, Luka (author), Drevenšek Olenik, Irena (author), Unold, Heiko (author), Shamonin, Mikhail (author)

An effective method for on-demand control over the impact dynamics of droplets on a magnetoresponsive surface is reported. The surface is comprised of micrometer-sized lamellas from a magnetoactive elastomer on a copper substrate. The surface itself is fabricated using laser micromachining. The orientation of the lamellae is switched from edge-on (orthogonal to the surface) to face-on (parallel to the surface) by changing the direction of a moderate (<250 mT) magnetic field. This simple actuation technique can significantly change the critical velocities of droplet rebound, deposition, and splashing. Rebound and deposition regimes can be switched up to Weber number We < 13 ± 3, while deposition and splashing can be switched in the range of 32 < We < 52. Because a permanent magnet is used, no permanent power supply is required for maintaining the particular regime of droplet impact. The presented technology is highly flexible and enables selective fabrication and actuation of microstructures on complex devices. It has great potential for applications in soft robotics, microfluidics, and advanced thermal management.

• Language: English
• Keywords: magnetoactive elastomers, laser micromachining, wettability
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 10 str.
• Numbering: Vol. 10, art. 2202471
• PID: 20.500.12556/RUL-168613
• UDC: 620.3
• ISSN on article: 2196-7350
• DOI: 10.1002/admi.202202471
• COBISS.SI-ID: 145255427
• Publication date in RUL: 18.04.2025

Record is a part of a journal

• Title: Advanced materials interfaces
• Publisher: Wiley-VCH
• ISSN: 2196-7350
• COBISS.SI-ID: 522945561

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: magnetoaktivni elastomeri, lasersko strukturiranje, omočljivost